Method of making aluminum-containing zeolite with IFR structure

ABSTRACT

Zeolites having the IFR structure and containing aluminum in their crystal structure can be made by preparing a reaction mixture comprising a zeolite which is an active source of aluminum oxide, an active source of alkali metal oxide, an active source of an oxide of a tetravalent element, an organic template selected from the group consisting of a 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation and a N-benzyl quinuclidinium cation, and maintaining the reaction mixture under conditions sufficient to form crystals of the zeolite.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for preparingaluminum-containing crystalline zeolites having the IFR structure (“IFRzeolite”) using a zeolite as an active source of aluminum oxide.

[0003] 2. State of the Art

[0004] IFR zeolites are known. U.S. Pat. No. 5,437,855, issued Aug. 1,1995 to Valyocsik, discloses a zeolite, designated “MCM-58”, having theIFR structure prepared using a benzylquinuclidinium organic directingagent. However, it does not disclose the use of a zeolite as a source ofaluminum for MCM-58. U.S. Pat. No. 5,441,721, issued Aug. 15, 1995 toValyocsik, also discloses MCM-58, but prepared using a benzyltropaniumorganic directing agent. Use of a zeolite as the source of aluminum forMCM-58 is not disclosed. It has been discovered that when a zeolite(Na—Y) is used as the source of aluminum and benzyltropanium is used asthe structure directing agent, the only zeolite produced was FAU (astarting material). No zeolite with the IFR structure was made (seeComparative Example B below). Both patents are incorporated by referenceherein in their entirety. U.S. Pat. No. 5,653,956, issued Aug. 5, 1997to Zones, discloses a zeolite, designated SSZ-42, prepared using anorganic templating agent selected from the group consisting of1-benzyl-4-aza-1-azonia-bicyclo [2.2.2] octane cations andN-benzyl-1-azabicyclo[2.2.2]octane cations. The SSZ-42 may containoxides of boron, aluminum, gallium, iron or titanium, but at least 50%of those oxides must be boron oxide. Zeolites are disclosed as apossible source of aluminum or boron (see col. 8). In Example 14, analuminum-containing SSZ-42 is made, but the aluminum is added to theSSZ-42 by post-treatment after the boron-containing SSZ-42 was prepared.Likewise, in Example 16 a boron- and gallium-containing SSZ-42 is madeby adding gallium by post-treatment of previously made SSZ-42. InExample 20, an aluminum- and boron-containing (50/50) SSZ-42 is prepareddirectly using sodium borate as the source of boron and sodium aluminumtrihydrate as the source of aluminum. U.S. Pat. No. 5,653,956 isincorporated herein by reference in its entirety.

[0005] U.S. Pat. No. 5,340,563, issued Aug. 23, 1994 to Zones et al.,discloses an improved method for preparing large pore zeolites. Themethod involves preparing a reaction mixture containing a sourcezeolite, an alkali metal, nitrogen containing organic cation, a sourceof silica and water. The source zeolite contains sodalite substructuresand has a tetrahedra atom density of less than about 15 TO₂ per 1000Angstroms³. Examples of zeolites prepared by this method are SSZ-25,SSZ-31, SSZ-37, beta and ZSM-12. Zeolites A, N-A, ZK-4, faujasite, X, Y,ZK-5 and rho are disclosed as source zeolites. U.S. Pat. No. 5,340,563is incorporated by reference herein in its entirety.

[0006] U.S. Pat. No. 4,503,024, issued Mar. 5, 1985 to Bourgogne et al.,discloses synthesizing zeolites using zeolites as reactants. It doesnot, however, disclose the synthesis of a zeolite having the IFRstructure.

SUMMARY OF THE INVENTION

[0007] In accordance with the present invention there is provided amethod for preparing a zeolite having the IFR structure comprising:

[0008] (a) preparing a reaction mixture comprising (1) a zeolite whichis an active source of aluminum oxide, (2) an active source of alkalimetal oxide, (3) an active source of an oxide of a tetravalent element,and (4) an organic template selected from the group consisting of aN-benzyl-1,4-diazabicyclo[2.2.2] octane cation and a N-benzylquinuclidinium cation, wherein said reaction mixture has a compositionin terms of mole ratios of oxides falling within the following ranges:

[0009] YO₂/Al₂O₃ about 5 to about 100

[0010] OH⁻/YO₂ about 0.05 to about 0.50

[0011] Q/YO₂ about 0.10 to about 1.0

[0012] M_(2/n)/YO₂ about 0.005 to about 0.50

[0013] H₂O/YO₂ about 3 to about 100

[0014] Q/Q+M_(2/n) about 0.50 to about 0.95

[0015] wherein Y is silicon, germanium or mixtures thereof, Q is an1-benzyl-4-aza-1-azonia bicyclo[2.2.2]octane cation or N-benzylquinuclidinium cation, M is an alkali metal cation or alkaline earthmetal cation and n is the valence of M; and (b) maintaining the reactionmixture under conditions sufficient to form crystals of the IFR zeolite.

[0016] Also provided in accordance with the present invention is anessentially boron-free zeolite having a composition, as synthesized andin the anhydrous state, in terms of mole ratios as follows:

[0017] YO₂/Al₂O₃ about 5 to about 100

[0018] OH³¹/YO₂ about 0.05 to about 0.50

[0019] Z/YO₂ about 0.10 to about 1.0

[0020] M_(2/n)/YO₂ about 0.005 to about 0.50

[0021] H₂O/YO₂ about 3 to about 100

[0022] Z/Z+M_(2/n) about 0.50 to about 0.95

[0023] wherein Y, M and n are as defined above and Z is a1-benzyl-4-aza-1-azonia bicyclo[2.2.2]octane cation.

[0024] Further provided in accordance with the present invention is azeolite having the IFR crystal structure and having a composition, assynthesized and in the anhydrous state, in terms of mole ratios asfollows:

[0025] YO₂/Al₂O₃ about 5 to about 100

[0026] YO₂/B₂O₃ about 5 to about 100

[0027] OH⁻/YO₂ about 0.05 to about 0.50

[0028] Z/YO₂ about 0.10 to about 1.0

[0029] M_(2/n)/YO₂ about 0.005 to about 0.50

[0030] H₂O/YO₂ about 3 to about 100

[0031] Z/Z+M_(2/n) about 0.50 to about 0.95

[0032] wherein Y, M, and n are as defined above and Z is a1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation and wherein theamount of aluminum is greater than the amount of boron.

DETAILED DESCRIPTION OF THE INVENTION

[0033] Zeolites having the IFR structure are those which, aftercalcination, have a crystalline structure whose X-ray powder diffractionpattern includes the characteristic lines shown in Table I below: TABLEI CALCINED IFR ZEOLITE 2 Theta d/n Relative Intensity^((a)) 8.22 10.75VS 9.76 9.06 W 16.42 5.394 W 19.22 4.615 W 20.48 4.333 M 20.84 4.259 M21.48 4.134 W 21.72 4.088 W-M 23.68 3.754 W 24.06 3.696 W 24.94 3.568 W25.40 3.504 W 26.60 3.348 M 29.56 3.019 W

[0034] The variation in the scattering angle (two theta) measurements,due to instrument error and to differences between individual samples,is estimated at +/− 0.20 degrees.

[0035] The IFR zeolites prepared in accordance with this invention willtypically have a silica to alumina mole ratio of about 20 to about 80.

[0036] IFR zeolites can be prepared from an aqueous solution comprisingsources of an alkali metal oxide, the templating agent, an activesource(s) of desired tetravalent element oxide(s), and an activesource(s) of aluminum oxide. The reaction mixture should have acomposition, in terms of mole ratios, within the ranges shown in TableA. TABLE A IFR ZEOLITE REACTION MIXTURE Broad Preferred YO₂/Al₂O3 5 andgreater 15 and greater (to about 100) (to about 100) OH⁻/YO₂ 0.05 to0.50 0.15 to 0.30 Q/YO₂ 0.10 to 1.0 0.10 to 0.25 M_(2/N)/YO₂ 0.005 to0.50 0.03 to 0.10 H₂O/YO₂ 3 to 100 20 to 50 Q/Q + M_(2/n) 0.50 to 0.950.66 to 0.90

[0037] wherein Y is selected from the group consisting of silicon,germanium, and mixtures thereof, Q is comprised of1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cations or N-benzylquinuclidinium cations, M is an alkali metal cation or alkaline earthmetal cation and n is the valence of M.

[0038] In practice, aluminum-containing IFR zeolites are prepared by aprocess comprising:

[0039] (a) preparing an aqueous solution containing sources of theoxides listed in Table A above, wherein the source of aluminum is analuminum-containing zeolite, and a1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation or benzyltropaniumcation templating agent having an anionic counterion which is notdetrimental to the formation of the IFR zeolite;

[0040] (b) maintaining the aqueous solution under conditions sufficientto form crystals of IFR zeolite; and

[0041] (c) recovering the crystals of the IFR zeolite.

[0042] The 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cationtemplating agent has the following general formula:

[0043] The anion (X⁻) associated with the cation may be any anion whichis not detrimental to the formation of the zeolite. Representativeanions include halide, e.g., fluoride, chloride, bromide and iodide,hydroxide, acetate, sulfate, tetrafluoroborate, carboxylate, and thelike. Hydroxide is the most preferred anion.

[0044] The N-benzyl-1,4-diazabicyclo[2.2.2]octane cation (“benzylDABCO”) templating agent has the advantage that it is less expensivethan the benzylquinuclidinium organic directing agent of U.S. Pat. No.5,437,855 and the benzyltropanium organic directing agent of U.S. Pat.No. 5,441,721. However, it has been found that aluminosilicate IFRzeolites can not be made directly using conventional sources of alumina,such as sodium aluminate (see Comparative Example A below) when benzylDABCO is used as the templating agent. Rather, when benzyl DABCO is usedwith such a conventional source of alumina, a different zeolite results.Instead, a borosilicate IFR zeolite has to be prepared first, followedby exchange of the boron for aluminum. By using the source zeolites ofthis invention, aluminosilicate IFR zeolites can be directly preparedusing benzyl DABCO as the templating agent, resulting in significantcost savings.

[0045] The N-benzyl quinuclidinium cation templating agent has thefollowing formula:

[0046] where X⁻ is as defined above.

[0047] The reaction mixture used to prepare the IFR zeolites may alsocontain an active source of boron oxide, such as boric acid. When theboron source is present it is generally used in a YO₂/B₂O₃ mole ratio ofabout 5 to about 100, preferably from about 20 to about 100, where YO₂is defined above.

[0048] Typical sources of silicon oxide include silicates, silicahydrogel, silicic acid, fumed silica, colloidal silica, tetra-alkylorthosilicates, and silica hydroxides.

[0049] A zeolite reagent provides the source of aluminum for the IFRzeolite. In some cases, the source zeolite may provide a source ofsilica. Use of a source zeolite reagent as a source of alumina isdescribed in aforementioned U.S. Pat. No. 5,340,563.

[0050] The term “source zeolite” as used herein means an aluminosilicatezeolite used as a reactant in a reaction mixture to produce a zeolitehaving the IFR structure. The source zeolite used in accordance withthis invention contains sodalite substructures and has a tetrahedra atomdensity of less than about 15 TO₂/1000 Angstroms³ (TO₂ representing thetetrahedral oxides in the crystal structure). Preferably, the sourcezeolite is zeolite A, N-A, ZK-4, faujasite, X, Y, ZK-5 or rho. Thesilica to alumina mole ratio in these source zeolite should be fromabout 2 to about 20. Preferably, the silica to alumina mole ratio inthese source zeolites should be from about 2 to about 10, and mostpreferably from about 2 to about 5.

[0051] The term “sodalite substructures” as used herein means atruncated octahedron having 36 edges, 24 vertices, six square faces, andeight hexagonal faces with a tetrahedral atom located at each vertex.Oxygen atoms are located between the tetrahedral atoms, but notnecessarily on the edge.

[0052] Tetrahedra atom densities for various zeolitic structures isgiven in more detail in “Zeolite Molecular Sieves” by D. W. Breck(1984), the disclosure of which is incorporated by reference herein.

[0053] The use of source zeolites having sodalite structures and whichhave a tetrahedra atom density of less than about 15 TO₂/1000 Angstroms³allows a relatively smaller concentration of the organic template to bepresent in the reaction mixture. Because one can use lower amounts ofthe template, and because the source zeolite can be used in the ammoniumform as well as the alkali metal form, preferably as the sodium form ormixtures of ammonium and sodium forms, lower cost zeolites may beobtained.

[0054] Zeolite A and the conventional preparation thereof is describedin U.S. Pat. No. 2,882,243. Zeolite N-A and the conventional preparationthereof is described in U.S. Pat. No. 3,306,922. Zeolite ZK-4 and theconventional preparation thereof is described in U.S. Pat. No.3,247,195. Zeolite X and the conventional preparation thereof isdescribed in U.S. Pat. No. 2,882,244. Zeolite Y and the conventionalpreparation thereof is described in U.S. Pat. No. 3,130,007. ZeoliteZK-5 and the conventional preparation thereof is described in U.S. Pat.No. 3,247,195. Zeolite rho and the conventional preparation thereof isdescribed in U.S. Pat. No. 3,904,738. The disclosures of these patentsare incorporated by reference herein in their entirety.

[0055] Typically, an alkali metal hydroxide, such as the hydroxide ofsodium, potassium, lithium, or cesium is used in the reaction mixture;however, this component can be omitted so long as the equivalentbasicity is maintained. The templating agent may be used to providehydroxide ion. Thus, it may be beneficial to ion exchange, for example,a hydroxide anion for a halide ion in the templating agent, therebyreducing or eliminating the alkali metal hydroxide quantity required.The alkali metal cation may be part of the as-synthesized crystallineoxide material, in order to balance valence electron charges therein.

[0056] The reaction mixture is maintained at an elevated temperatureuntil the crystals of the zeolite are formed. This hydrothermalcrystallization is usually conducted under autogenous pressure, at atemperature between 100° C. (212° F.) and 200° C. (392° F.), preferablybetween 135° C. (275° F.) and 180° C. (356° F.). The crystallizationperiod is typically greater than 1 day and preferably from about 3 daysto about 7 days. The zeolite can be prepared with or without mildstirring or agitation.

[0057] During the hydrothermal crystallization step, the IFR zeolitecrystals can be allowed to nucleate spontaneously from the reactionmixture. However, the use of IFR zeolite crystals as seed material canbe advantageous in decreasing the time necessary for completecrystallization to occur. In addition, seeding can lead to an increasedpurity of the product obtained by promoting the nucleation and/orformation of IFR zeolite over any undesired phases. When used as seeds,IFR zeolite crystals are added in an amount sufficient to direct and/oraccelerate crystallization, i.e., typically between about 0.1 and about10% of the weight of silica used in the reaction mixture.

[0058] Once the zeolite crystals have formed, the solid product isseparated from the reaction mixture by standard mechanical separationtechniques such as filtration. The crystals are water-washed and thendried, e.g., at 90° C. (194° F.) to 150° C. (302° F.) for from 8 to 24hours, to obtain the as-synthesized, IFR zeolite crystals. The dryingstep can be performed at atmospheric pressure or under vacuum.

[0059] Aluminum-containing IFR zeolites are useful in hydrocarbonconversion reactions. Hydrocarbon conversion reactions are chemical andcatalytic processes in which carbon containing compounds are changed todifferent carbon containing compounds. Examples of hydrocarbonconversion reactions in which these zeolites are expected to be usefulinclude catalytic cracking, hydrocracking, dewaxing, alkylation, andolefin and aromatics formation reactions.

[0060] A primary advantage of the present invention is thataluminum-containing IFR zeolites can be made directly, i.e., there is noneed to first prepare a boron-containing IFR zeolite and then substitutealuminum for the boron in the zeolite. Thus, the present inventionprovides as-synthesized, aluminum-containing, essentially boron-free IFRzeolites that contain the N-benzyl-1,4-diazabicyclo[2.2.2] octane cationorganic template. As used in this context, the term “essentiallyboron-free” means that the as-synthesized zeolite contains less thanabout 500 ppm.

[0061] The present invention also provides a zeolite having the IFRcrystal structure in the as-synthesized state (i.e., prior to removal ofthe organic template from the zeolite) that contains both aluminum andboron. In this case, the amount of aluminum contained in the crystalstructure is greater than the amount of boron contained in the crystalstructure. In other words, of the combined amount of aluminum and boronin the crystal structure, less than 50%, preferably less than 30%, isboron.

EXAMPLES

[0062] The following examples demonstrate but do not limit the presentinvention.

Example 1 Synthesis of 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octaneCation

[0063] 145 Grams of 1,4-diazabicyclo[2.2.2]octane (commonly referred toas “DABCO”) is dissolved in 2.5 liters of ethyl acetate and chilled to0° C. (32° F.). 209 Grams of benzyl bromide is added dropwise while thechilled solution is stirred. Caution should be exercised because thereaction is rapid and requires cooling. The product is collected byfiltration and recrystallized from a minimum of warm methanol. Therecrystallized product gives a microanalysis and NMR pattern consistentwith the 1:1 adduct. The quaternary ammonium compound is ion exchangedusing hydroxide exchange resin AG 1-X8 from BioRad. The exchangedsolution is titrated for molarity and the yield of exchange is greaterthan 90%. The resulting compound is designated Template A.

Example 2 Synthesis of IFR Zeolite

[0064] 2.0 Millimoles of Template A is combined with 2.0 millimoles ofNaOH in 8 cc water. 0.28 Grams of Y zeolite (LZY-52 from Union CarbideCorporation, SiO₂/Al₂O₃ mole ratio near 5) is added in as well as 0.72grams of CAB-O-SIL M-5, a fumed silica. The reaction mixture is heatedin the Teflon cup of a 23 ml volume Parr digestion bomb, rotating on aspit at 43 RPM while being heated to 160° C. The reaction is heated for6 days under these conditions and then cooled. The pH having risenwithin the reactor to greater than 12, it is deemed that organozeoliteproduct has formed. The product is collected by filtration, givensubsequent washing and drying and then analyzed by X-ray diffraction.The product is an IFR zeolite with an X-ray pattern consistent withTable I above. The product contains a SiO₂/Al₂O₃ mole ratio (SAR) of 35as determined by wet chemical methods.

Examples 3-17 Synthesis of IFR Zeolite

[0065] In the following examples the SAR is varied in the runs by usingthe conditions of Example 2, and either increasing or decreasing thequantity of CAB-O-SIL. The conditions and XRD data results are given inTable B. TABLE B VARIATION IN SAR EX. NO. REACTANT SAR XRD PRODUCT(S) 320 IFR zeolite and some unreacted LZY-52 4 24 IFR zeolite and someLZY-52 5 28 IFR zeolite and a little remaining LZY52 6 32 IER zeolite 736 (Ex. 2) IFR zeolite 8 40 IFR zeolite 9 44 IFR zeolite 10 47 IFRzeolite 11 50 IFR zeolite 12 60 IFR zeolite 13 64 IFR zeolite 14 72 IFRzeolite 15 80 IFR zeolite and a trace of ZSM- 12 16 90 IFR zeolite and atrace of ZSM-12 17 100 ZSM-12 and LZY-52

Examples 18-20 Synthesis of Aluminoborosilicate IFR Zeolite

[0066] In the following reactions, the procedure is used as in Example 2except variable amounts of boron, as sodium borate, are added to providean IFR zeolite product containing both boron and aluminum substitutedinto the lattice. Table C below shows the ratios of boron and aluminumand the corresponding zeolite product(s). TABLE C Ex. No. Al/ B ratio inreaction Product(s) 18 1 (50/50) IFR zeolite & trace of beta 19 2(66/33) IFR zeolite & trace of beta 20 4 (80/20) IFR zeolite & a littleLZY-52

Example 21 Micropore Volume

[0067] One of the advantages of this synthetic method is the productionof an active aluminosilicate or aluminoborosilicate zeolite materialwith a high micropore volume, conducive to higher catalytic activity.The product of Example 2 is calcined to 1100° F. (593° C.), in stagesand under a stream of nitrogen with a very small air bleed. The stagesto 125° C. (257° F.) at 50° C. (122° F.)/hr, hold for two hours, 50° C.(122° F.)/hr to 540° C. (1004° F.), hold for four hours, 50° C. (122°F.)/hr to 593° C. (1100° F.) with a final hold for four hours. Thecalcined material is then ion-exchanged twice with ammonium nitrate,followed by a washing and drying step. The micropore volume, determinedby use of nitrogen as adsorbate, is found to be 0.20 cc/gm. This valuematches that found for the calcined IFR borosilicate zeolite SSZ-42 (seeExample 12 in U.S. Pat. No. 5,653,956), and is in good agreement withthe value expected from the structure determination for SSZ-42 (Chen etal., J. Chem. Soc. Chem. Comm., pg. 1775, 1997). This demonstrates thatthere is no pore blockage for this product.

Example 22 Constraint Index

[0068] The utility of the product material can be seen by subjecting theproduct of Example 21 to a catalytic cracking experiment using theConstraint Index determination. 0.50 Gram of 20-40 mesh granules (afterpelletization to 3000 psi and pellet breakup) of the product of Example21 is packed into a ¼ inch stainless steel reactor tube with alundum onboth sides of the zeolite bed. The reactor is placed in a Lindburgfurnace and heated to 540° C. (1004° F.) for drying. At 125° C. (257°F.) helium is introduced into the reactor at 10 cc/minute andatmospheric pressure. The temperature is gradually raised to 288° C.(550° F.) over 40 minutes. Feed is introduced by means of a syringe pumpat a rate of 0.62 cc/hr of a 50/50 (v/v) mixture of n-hexane and3-methylpentane. Direct sampling onto a gas chromatograph is begun atten minutes.

[0069] This material gives a C.I. conversion of 93% at 10 minuteson-stream at a low temperature of 550° F. (288° C.). This activitycompares favorably with the activity of the very strong acid zeolitecatalysts, beta and SSZ-26.

Example 23 Larger Scale Synthesis of IFR Zeolite

[0070] 605 Milliliters of 0.93M aqueous solution of Template A (562 mmolof Template A), 375 ml of 1.0 N aqueous solution of NaOH (375 mmol ofNaOH), 1000 ml of water (total water=102.23 mmol), 201 grams ofCAB-O-SIL M-5 silica (3.283 moles silica) and 64.5 grams LZY-52 zeolite(0.5 mole silica, 0.218 mole Al, 0.218 mole Na, 0.9 mole water) are allmixed in a 1-gallon steel liner (the reagents are listed in order ofmixing). To the resulting gel, small amounts (on the order of 1.5 or 3weight percent based on the weight of the silica) of aluminum-containingIFR zeolite crystals are added as seeds. The gel is then heated in anautoclave at 160° C. at 100 rpm for 120 hours. When 1.5 wt. % of seedsis used, the resulting product contains IFR zeolite as the majorcrystallization product, with beta zeolite as a minor impurity and atrace amount of MOR. When 3 wt. % seeds is used, IFR zeolite is obtainedwith only a trace amount of MOR.

Example 24 Synthesis of IFR Zeolite Using Na—X Zeolite

[0071] 2.42 ml of 0.93 M solution of benzyl DABCO hydroxide (2.25 mmolof benzyl DABCO), 1.5 gm of 1.0 N sodium hydroxide solution and enoughde-ionized water to reach a total weight of 7.4 gm are added to a 23 ccTeflon liner. To the resulting mixture is added 0.175 gm of Na—X zeolite(Al/Si=1), and 0.86 gm of CAB-O-SIL M-5 silica. The resulting gel isplaced in a steel reactor and heated at 160° C. while being tumbled at43 rpm. After heating and tumbling for six days, the reaction iscomplete. The resulting mixture (a solution with settled fine solids) isfiltered and the solids are washed with deionized water several times,and then air dried overnight. The reaction yields 0.95 gm of a zeolitehaving the IFR structure, with a small amount of Gismondine (P zeolite)impurity, as indicated by X-ray diffraction analysis.

Example 25 Synthesis of IFR Zeolite Using Na-A Zeolite

[0072] 2.42 ml of 0.93 M solution of benzyl DABCO hydroxide (2.25 mmolof benzyl DABCO), 1.5 gm of 1.0 N sodium hydroxide solution and enoughde-ionized water to reach a total weight of 7.4 gm are added to a 23 ccTeflon liner. To the resulting mixture is added 0.175 gm of Na-A zeolite(Al/Si=1), and 0.86 gm of CAB-O-SIL M-5 silica. The resulting gel isplaced in a steel reactor and heated at 160° C. while being tumbled at43 rpm. After heating and tumbling for six days, the reaction iscomplete. The resulting mixture (a solution with settled fine solids) isfiltered and the solids are washed with deionized water several times,and then air dried overnight. The reaction yields 1.0 gm of a zeolitehaving the IFR structure, with a trace amount of Gismondine (P zeolite)impurity, as indicated by X-ray diffraction analysis.

Example 26 Synthesis of IFR Zeolite Using N-Benzyl Quinuclidinium Cation

[0073] In a 23 cc. Teflon liner is placed 4.75 ml. of 0.475M solution ofN-benzyl quinuclidinium hydroxide (2.25 mmol. N-benzyl quinuclidiniumhydroxide), 1.5 g. of 1N sodium hydroxide. Water is added until a totalweight of 7.36 g. is reached. To the resulting solution is added 0.26 g.of LZY-52 zeolite, and 0.81 g. of CAB-O-SIL M-5 fumed silica. Theresulting gel is sealed in the Teflon liner and placed in a steel Parrreactor and heated in an oven at 160° C. while rotating at 43 rpm. Thereaction is monitored by following the change in the pH of the reactionmixture and by Scanning Electron Microscopy. The reaction requires 12days to complete. The reaction mixture is then filtered and the obtainedsolid material is washed several times with deionized water andair-dried over night. The reaction yields 1.1 g. of a mixture of an IFRzeolite and a FAU zeolite (the starting reagent), as determined by X-raydiffraction analysis.

Comparative Example A Use of Benzyl DABCO and Sodium Aluminate

[0074] 2.42 Ml of 0.93 M solution of benzyl DABCO hydroxide (2.25 mmolof benzyl DABCO), 1.5 gm of 1.0 N sodium hydroxide solution and enoughde-ionized water to reach a total weight of 7.38 gm are added to a 23 ccTeflon liner. To the resulting mixture is added 0.0734 gm of sodiumaluminate (containing 17.27% water by weight), and 0.91 gm of CAB-O-SILM-5 silica. The resulting gel is placed in a steel reactor and heated at160° C. while being tumbled at 43 rpm. After heating and tumbling for 12days, the reaction is complete. The resulting mixture (a solution withsettled solids) is filtered and the solids are washed with deionizedwater several times, and then air dried overnight. The reaction yields1.1 gm of a beta zeolite, as indicated by X-ray diffraction analysis. Nozeolite having the IFR structure is observed.

Comparative Example B Use of Benzyl Tropanium Cation

[0075] In a 23 cc. Teflon liner is placed 4 ml. of 0.57M solution ofN-benzyl tropanium hydroxide (2.25 mmol. N-benzyltropanium hydroxide),1.5 g. of 1N sodium hydroxide. Water is added until a total weight of7.4 g. is reached. To the resulting solution is added 0.26 g. of LZY-52zeolite and 0.81 g. of CAB-O-SIL M-5 fumed silica is added. Theresulting gel is sealed in the Teflon liner and placed in a steel Parrreactor and heated in an oven at 160° C. while rotating at 43 rpm. Thereaction is monitored by following the change in the pH of the reactionmixture and by Scanning Electron Microscopy. After heating for 24 daysthe reaction mixture is filtered and the obtained solid material iswashed several times with deionized water and air-dried over night. Thereaction yields 1.0 g. of amorphous material, FAU zeolite (startingreagent), and a trace of layered material, as determined by X-raydiffraction analysis. No IFR zeolite is observed.

Comparative Example C Use of N-Benzyl Tropanium Cation and Sodium Borate

[0076] In a 23 cc. Teflon liner is placed 5.25 ml. of 0.57M solution ofN-benzyl tropanium hydroxide (3 mmol. N-benzyl tropanium hydroxide), 1.2g. of 1N sodium hydroxide. Water is added until a total weight of 12 g.is reached. To the resulting mixture is added 0.06 g. of sodium boratedecahydrate, and the mixture is stirred until the sodium boratedissolves. Finally, 0.9 g. of CAB-O-SIL M-5 fumed silica is added. Theresulting gel is sealed in the Teflon liner and placed in a steel Parrreactor and heated in an oven at 160° C. while rotating at 43 rpm. Thereaction is monitored by following the change in the pH of the reactionmixture and by Scanning Electron Microscopy. The reaction requires 18days to complete. The reaction mixture is then filtered and the obtainedsolid material is washed several times with deionized water andair-dried over night. The reaction yields 0.8 g. of a boron-containingIFR zeolite and a trace amount of layered material, as determined byX-ray diffraction analysis.

Comparative Example D Use of Aluminum Sulfate as the Aluminum Source

[0077] In a 23 cc Teflon liner is placed 5.22 ml of 0.93M solution ofbenzyl DABCO-OH (4.85 mmol of benzyl DABCO), and 1.5 gm of 1.0N sodiumhydroxide solution. De-ionized water is added until the total weightreaches 7.36 gm. To this mixture, 0.293 GM of aluminum sulfateoctadecahydrate (Al₂(SO₄)₃ 18H₂O) and 0.91 gm of CAB-O-SIL-M-5 areadded. The resulting gel is placed in a steel reactor and heated at 160°C. and tumbling at 43 rpm. After heating and tumbling for 12 days, thereaction is complete. The resulting mixture (a solution with settledsolids) is filtered and the solids are washed with de-ionized waterseveral times and then dried in an oven at 120° C. for 30 minutes. Thereaction yields 1 gm of BETA zeolite as indicated by XRD analysis. NoIFR zeolite is observed. (Organic/Si=0.32; Al/Si=0.059; Na/Si=0.15;OH/Si=0.25: H₂O/Si=27). In this reaction protons are generated due tothe use of aluminum sulfate as an aluminum source. The amount ofhydroxide takes into account hydroxide lost from balancing the protonsfrom the aluminum sulfate. To account for the consumed hydroxide by thegenerated protons and to keep the OH/Si ratio in the desired range, moreof the organic template is added as the hydroxide source. In comparison,when the extra hydroxide is added in the form of NaOH, the reactionmixture remains as a gel after heating for five weeks.

What is claimed is:
 1. A method for preparing a zeolite having the IFR structure comprising: (a) preparing a reaction mixture comprising (1) a zeolite which is an active source of aluminum oxide, (2) an active source of alkali metal oxide, (3) an active source of an oxide of a tetravalent element, and (4) an organic template selected from the group consisting of a 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation and a N-benzyl quinuclidinium cation, wherein said reaction mixture has a composition in terms of mole ratios of oxides falling within the following ranges: YO₂/Al₂O₃ about 5 to about 100 OH⁻/YO₂ about 0.05 to about 0.50 Q/YO₂ about 0.10 to about 1.0 M_(2/n)/YO₂ about 0.005 to about 0.50 H₂O/YO₂ about 3 to about 100 Q/Q+M_(2/n) about 0.50 to about 0.95 wherein Y is silicon, germanium or mixtures thereof, Q is an 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation or N-benzyl quinuclidinium cation, M is an alkali metal cation or alkaline earth metal cation and n is the valence of M; and (b) maintaining the reaction mixture under conditions sufficient to form crystals of the IFR zeolite.
 2. The method of claim 1 wherein the reaction mixture has the following composition: YO₂/Al₂O₃ about 15 to about 100 OH⁻/YO₂ about 0.15 to about 0.30 OH—/YO₂ about 0.10 to about 0.25 M_(2/n)/YO₂ about 0.03 to about 0.10 H₂O/YO₂ about 20 to about 50 Q/Q+M_(2/n) about 0.66 to about 0.90.
 3. The method of claim 1 wherein the reaction mixture further comprises an active source of boron oxide in a mole ratio of oxides of about 5 to about 100 YO₂/B₂O₃.
 4. The method of claim 2 wherein the reaction mixture further comprises an active source of boron oxide in a mole ratio of oxides of about 5 to about 100 YO₂/B₂O₃.
 5. The method of claim 3 wherein the amount of boron is less than the amount of aluminum.
 6. The method of claim 4 wherein the amount of boron is less than the amount of aluminum.
 7. The method of claim 1 wherein the active source of aluminum oxide is a zeolite that contains sodalite substructures and has a tetrahedra atom density of less than about 15 TO₂/1000Angstroms³.
 8. The method of claim 1 wherein the active source of aluminum oxide is Y zeolite in the sodium form.
 9. The method of claim 1 wherein the active source of aluminum oxide is zeolite A in the sodium form.
 10. The method of claim 1 wherein the active source of aluminum oxide is zeolite N-A in the sodium form.
 11. The method of claim 1 wherein the active source of aluminum oxide is zeolite ZK-4 in the sodium form.
 12. The method of claim 1 wherein the active source of aluminum oxide is faujasite in the sodium form.
 13. The method of claim 1 wherein the active source of aluminum oxide is zeolite X in the sodium form.
 14. The method of claim 1 wherein the active source of aluminum oxide is zeolite ZK-5 in the sodium form.
 15. The method of claim 1 wherein the active source of aluminum oxide is zeolite rho in the sodium form.
 16. The method of claim 1 wherein the organic template comprises an 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation.
 17. The method of claim 1 wherein the organic template comprises an N-benzyl-quinuclidinium cation.
 18. An essentially boron-free zeolite the IFR crystal structure and having a composition, as synthesized and in the anhydrous state, in terms of mole ratios as follows: YO₂/Al₂O₃ about 5 to about 100 OH⁻/YO₂ about 0.05 to about 0.50 Z/YO₂ about 0.10 to about 1.0 M_(2/n)/YO₂ about 0.005 to about 0.50 H₂O/YO₂ about 3 to about 100 Z/Z+M_(2/n) about 0.50 to about 0.95 wherein Y is silicon, germanium or a mixture thereof, M is an alkali metal cation, alkaline earth metal cation or mixtures thereof, n is the valence of M; and Z is a 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation.
 19. A zeolite having the IFR crystal structure and having a composition, as synthesized and in the anhydrous state, in terms of mole ratios as follows: YO₂/Al₂O₃ about 5 to about 100 YO₂/B₂O₃ about 5 to about 100 OH⁻/YO₂ about 0.05 to about 0.50 Z/YO₂ about 0.10 to about 1.0 M_(2/n)/YO₂ about 0.005 to about 0.50 H₂O/YO₂ about 3 to about 100 Z/Z+M_(2/n) about 0.50 to about 0.95 wherein Y is silicon, germanium or a mixture thereof; M is an alkali metal cation, alkaline earth metal cation or mixtures thereof; n is the valence of M; and Z is a 1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane cation and wherein the amount of aluminum is greater than the amount of boron.
 20. The zeolite of claim 17 wherein of the combined amount of boron and aluminum, less than 30% is boron. 